scholarly journals The absence of a short period in the WN5 star EZ Canis Majoris

1995 ◽  
Vol 163 ◽  
pp. 56-57
Author(s):  
Igor I. Antokhin ◽  
Jean-François Bertrand ◽  
Robert Lamontagne ◽  
Anthony F.J. Moffat

Several suggestion have been put forward to explain the 3.d766 periodicity of EZ CMa (WR6): (i) WR+c system; (ii) rotating single WR star; (iii) pulsations (non—radial (NRP) or radial) with frequency reduced by some kind of filtering in the wind. In this paper, we report on a photometric investigation based on a long continuous observing run, in an attempt to verify whether EZ CMa does in fact show a unique periodicity. In particular, this work was motivated by the claim by Gosset & Vreux (1987), based on the data from Lamontagne et al. (1986, hereafter LML), that EZ CMa may have a shorter period besides the one at 3.d766, a frequency close to but not equal to the third harmonic of the 3.d766 period.

1987 ◽  
Vol 8 (7) ◽  
pp. 196-199
Author(s):  
Martin J. Drell

When I arrived home, my wife told me to call a personal friend of ours who needed some advice. All my wife knew was that our friend, Mary, had just found out that the baby she was about to deliver was deformed and might not live. Mary wanted to talk with me about how to handle the matter with Barry, her son who was nearly 4 years old. Calls like this are always difficult ones, and it was with some trepidation that I called. Mary answered. Her voice quivered as she talked. The history unfolded piecemeal throughout the one-half hour phone call. From the beginning, Mary believed that something was wrong with her pregnancy, that somehow it had not "felt right" From a medical stadpoint, however, there were only minor problems. At the beginning of the third trimester, she had a short period of spotting. The obstetrician had Mary lie down and not exert herself. During this period of rest, Barry was told specifically not to jump on his mother, because it might hurt the baby. The spotting did not recur and the pregnancy progressed, supposedly without a hitch. As the delivery time approached, sonography was done to check on the health of the fetus. The test was done because of the mother's past history of having delivered Barry prematurely and having had a subsequent miscarriage.


2021 ◽  
Vol 2015 (1) ◽  
pp. 012048
Author(s):  
A D Golinskaya ◽  
A M Smirnov ◽  
V N Mantsevich ◽  
M V Kozlova ◽  
D A Kurtina ◽  
...  

Abstract The photoluminescence and nonlinear transmission of atomically thin population of colloidal CdSe rolled-up nanosheets were investigated at the one-photon stationary excitations of excitons by the third harmonic of Nd3+:YAP laser pulses. It was revealed that the nonlinear optical response of the nanoscrolls is strongly influenced by multiwalled rolled-up structure. The broadening of exciton band and the red shift of the photoluminescence were observed and explained by coupling effect within the folded scroll-layers.


2009 ◽  
Vol 14 (3) ◽  
pp. 3-6
Author(s):  
Robert J. Barth

Abstract “Posttraumatic” headaches claims are controversial because they are subjective reports often provided in the complex of litigation, and the underlying pathogenesis is not defined. This article reviews principles and scientific considerations in the AMAGuides to the Evaluation of Permanent Impairment (AMA Guides) that should be noted by evaluators who examine such cases. Some examples in the AMA Guides, Sixth Edition, may seem to imply that mild head trauma can cause permanent impairment due to headache. The author examines scientific findings that present obstacles to claiming that concussion or mild traumatic brain injury is a cause of permanent headache. The World Health Organization, for example, found a favorable prognosis for posttraumatic headache, and complete recovery over a short period of time was the norm. Other studies have highlighted the lack of a dose-response correlation between trauma and prolonged headache complaints, both in terms of the frequency and the severity of trauma. On the one hand, scientific studies have failed to support the hypothesis of a causative relationship between trauma and permanent or prolonged headaches; on the other hand, non–trauma-related factors are strongly associated with complaints of prolonged headache.


2004 ◽  
Vol 34 (136) ◽  
pp. 455-468
Author(s):  
Hartwig Berger

The article discusses the future of mobility in the light of energy resources. Fossil fuel will not be available for a long time - not to mention its growing environmental and political conflicts. In analysing the potential of biofuel it is argued that the high demands of modern mobility can hardly be fulfilled in the future. Furthermore, the change into using biofuel will probably lead to increasing conflicts between the fuel market and the food market, as well as to conflicts with regional agricultural networks in the third world. Petrol imperialism might be replaced by bio imperialism. Therefore, mobility on a solar base pursues a double strategy of raising efficiency on the one hand and strongly reducing mobility itself on the other.


2011 ◽  
Vol 13 (2) ◽  
pp. 201-171
Author(s):  
Nāṣir Al-Dīn Abū Khaḍīr

The ʿUthmānic way of writing (al-rasm al-ʿUthmānī) is a science that specialises in the writing of Qur'anic words in accordance with a specific ‘pattern’. It follows the writing style of the Companions at the time of the third caliph, ʿUthmān b. ʿAffān, and was attributed to ʿUthmān on the basis that he was the one who ordered the collection and copying of the Qur'an into the actual muṣḥaf. This article aims to expound on the two fundamental functions of al-rasm al-ʿUthmānī: that of paying regard to the ‘correct’ pronunciation of the words in the muṣḥaf, and the pursuit of the preclusion of ambiguity which may arise in the mind of the reader and his auditor. There is a further practical aim for this study: to show the connection between modern orthography and the ʿUthmānic rasm in order that we, nowadays, are thereby able to overcome the problems faced by calligraphers and writers of the past in their different ages and cultures.


2013 ◽  
pp. 32-47
Author(s):  
S. V. Osipov

Geobotanical mapping of the territory in riverheads Bureya of 4500 sq.km is carried out and the map of a actual vegetation cover of scale 1 : 200 000 is prepared. The legend of the map is presented in the form of the text with three-level hierarchy of classes. At the heart of structure of a legend of the map such regularities of a vegetation cover, as its latitudinal zonality / altitudinal belts, situation in a relief and dynamic series lie. The largest divisions of the legend reflect, first, change of large classes of mesocombinations of vegetation at the level of belts and, secondly, distinction in a boreal - forestry belt between a vegetation cover of tops and slopes of mountains, on the one hand, and the bottoms of river valleys, with another. Divisions of the legend of the second level reflect, first, vegetation changes in the form of high-rise and barrier changes of subbelts, secondly, distinctions of a vegetation cover in different geomorphological conditions (small and average river valleys, northern slopes, etc.). Divisions of the legend of the second level correspond to dynamic series of units of the third level. Essential addition to it are block diagrams of dynamics of a vegetation cover.


Author(s):  
Patrick Colm Hogan

The introduction first sets out some preliminary definitions of sex, sexuality, and gender. It then turns from the sexual part of Sexual Identities to the identity part. A great deal of confusion results from failing to distinguish between identity in the sense of a category with which one identifies (categorial identity) and identity in the sense of a set of patterns that characterize one’s cognition, emotion, and behavior (practical identity). The second section gives a brief summary of this difference. The third and fourth sections sketch the relation of the book to social constructionism and queer theory, on the one hand, and evolutionary-cognitive approaches to sex, sexuality, and gender, on the other. The fifth section outlines the value of literature in not only illustrating, but advancing a research program in sex, sexuality, and gender identity. Finally, the introduction provides an overview of the chapters in this volume.


Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3194
Author(s):  
Adrian Petris ◽  
Petronela Gheorghe ◽  
Tudor Braniste ◽  
Ion Tiginyanu

The ultrafast third-order optical nonlinearity of c-plane GaN crystal, excited by ultrashort (fs) high-repetition-rate laser pulses at 1550 nm, wavelength important for optical communications, is investigated for the first time by optical third-harmonic generation in non-phase-matching conditions. As the thermo-optic effect that can arise in the sample by cumulative thermal effects induced by high-repetition-rate laser pulses cannot be responsible for the third-harmonic generation, the ultrafast nonlinear optical effect of solely electronic origin is the only one involved in this process. The third-order nonlinear optical susceptibility of GaN crystal responsible for the third-harmonic generation process, an important indicative parameter for the potential use of this material in ultrafast photonic functionalities, is determined.


2020 ◽  
Vol 499 (3) ◽  
pp. 3738-3748
Author(s):  
R H Østensen ◽  
C S Jeffery ◽  
H Saio ◽  
J J Hermes ◽  
J H Telting ◽  
...  

ABSTRACT The Kepler spacecraft observed the hot subdwarf star PHL 417 during its extended K2 mission, and the high-precision photometric light curve reveals the presence of 17 pulsation modes with periods between 38 and 105 min. From follow-up ground-based spectroscopy, we find that the object has a relatively high temperature of 35 600 K, a surface gravity of $\log g / {\rm cm\, s^{-2}}\, =\, 5.75$ and a supersolar helium abundance. Remarkably, it also shows strong zirconium lines corresponding to an apparent +3.9 dex overabundance compared with the Sun. These properties clearly identify this object as the third member of the rare group of pulsating heavy-metal stars, the V366-Aquarii pulsators. These stars are intriguing in that the pulsations are inconsistent with the standard models for pulsations in hot subdwarfs, which predicts that they should display short-period pulsations rather than the observed longer periods. We perform a stability analysis of the pulsation modes based on data from two campaigns with K2. The highest amplitude mode is found to be stable with a period drift, $\dot{P}$, of less than 1.1 × 10−9 s s−1. This result rules out pulsations driven during the rapid stages of helium flash ignition.


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